Thermionic valve



A. THERM ONl C VALVE Filed. Apzil '7 1925 7 Cdl LJ ma la 7 I N V E N T O Fi lilatented .laune 2. T1926.

THERMEONIC VALVE.,

Application ated April 7, 1925.

This invention relates to thermionic valves and its object is to provide a therl mionic valve which can be readily disassemblerl for renewal of a ruptured iilament t and in which provision is made for cooling the anode.

The thermionic valve also may have two grids and two anode plates exposed tothe electronic emission from a single iilament l@ in common and which can either be used in 'arallel in the same circuits or can be used independently for controlling diilerent circuits. i

The thermionic valve, according to the in l vention., consists of a stout annular glass member having a filament mounted across the central aperture of the member and within the thickness thereof, a metal grid mounted in the member on one or each side Q0 of the-filament, an anode'plate outside the grid or each grid, and a glass cap interitting each side of and sealed to the member.

Preferably a grid and plate are arranged on both sides of the central annular glass member.

Heat is conveyed from the anode plates by means of met-al foil liners in contact respectively with the plates and with an ample area of the glass caps.

A thermionic valve according to the invention is illustrated on the accompanying drawing, in which Fig. 1 is a longitudinal section of the valve.

Fig. 2 is an end elevation of the valve with one of the caps and liners removed.

Fig. 3 is a side elevation of a liner.

Fig. i shows a detail on a larger scale.`

a is a stout annular glass member.

b is an incandescible lament mounted across the central aperture of the glass member a at the middle of the thickness thereof and extending from and stretched between leads c, sealed through the wall of the glass 5 member a, and a light spring d anchored to the diametrally opposite side of the disc a.

Each face of the annular glass member a is recessed at a1, and glass egs e protrude axially from the base of eac recess a1.

A grid is formed on each side of the filament b by a wire f led in a zig-zag manner to and fro across the central aperture of the annular glass member a from one peg e to u another, and wound around each peg to retain the wire f against shpping. As indi- @arial No. 21,4251.

cated in Fig. 4 each peg e may be niclred or notched at an accessible portion better to retain the grid wire f against displacement along the pegs e and so changing its position relatively to the iilament b and the respective anode plate g, next to be described.

One end of each grid wire f is secured to a lead if sealed through the wall of the annular g ass member a and the other end of the grid wire It is anchored to the diametrally opposite peg e.

Against the ends of each of the two sets or pegs e is located a circular metal plate g, each of which plates g constitutes an anode.

An elongated closed ended cylindrical glass cap h abuts against each end face of the annular glass member a, and by a reduced portion e' entering the recess al, also bears lightly but firmly against the respective anode plate g. The plates g are thus held against the ends of the pegs e, in a manner permitting expansion and contraction in the direction of the planes of the plates g.

The internal surface of the cylindrical portion of each glass cap k is corrugated helically and a helically corrugated metal foil liner j is held in such corrugations with an end flange in contact with the respective anode plate g and interposed between same (itl titi

and the respective cap k. These liners j v serve to convey heat from the anodes g to the walls of the glass caps it, which would not be conveyed by convection owing to the vacuum which eventually reigns in the space Within the caps 11,. The external surfaces of the cylindrical portions of the glass caps 71, are formed with ribs 7c to radiate heat from the Walls thereof.

A hole g1 is formed in each plate g. This hole g1 is masked externally by a bracket plate Z, to which a lead g2, sealed through I the end of the respective glass cap L, is secured.

The caps h are sealed to the central annular glass member aby a glass bead m fused around the outer border of each abutting surface.

The s ace enclosed by the caps h and annular g ass member a is exhausted of air through an eventually sealed pip n in one of the glass caps lz, the vacuum being propagated through the holes g1 in the anode p ates g.

Direct electronic bombardment of the caps h through the holes g1 in the anode plates is prevented by these holes g1 being masked by the bracket plates Z.

The two grids f and the two anodes'g may be used in parallelby joining the grid leads f1 together and the anode leads g together, or may be used separately. -In the latter case one grid f and plate g may be used for controlling one circuit-and the other grid j and plate g for controlling another circult, or one such pair may be kept 1noperative in reserve.

The valve can be disassembled for replacement of one 0r more of its contained parts by grinding o one or both glass beads m.

o are metal bracket plates having holes in which the caps L are held. Thus the whole valvemay be conveniently supported as shown by being clipped between the plates o.

Obviously the grid and plate may .be omitted from one side of the annular glass member a.

The grid f may be a wire mesh.

I claim:

l. A thermionic valve consisting of a stout annular glass member, an incandescible filament mounted across the central aperture of and within the thickness of said member, a metal grid mounted in said member alongside said lament, an anode plate mounted outside said grid, and a glass cap laterally interfitting and sealed to said member.

2. A thermionic valve consisting of a stoutannular glass member, an incandescible filament mounted across the central aperture of and Within the thickness of said member, a metal grid mounted in said member alongside said ilament, an anode plate mounted outside said grid, a glass cap laterally on and sealed to said member, and ametal liner in said glass cap in contact with sald anode plate.

3. A thermionic valve consisting of a recessed stout annular glass member, an incandescible filament mounted across the central aperture of and within the thickness of said member, pegs on and protruding Within said recessed portion of said member, a

- metal grid mounted on said pegs in said member alongside said lament, an anode plate mounted outside said grid against the ends of said pegs, and aA glass cap laterally on-and sealed to said member and bearing against saidanode plate. i

-4.. A thermionic valve consistlng oa re- Acessed `st out annular glass member, anincandescible filament mounted across the central aperture of and Within the thickness of said: member, pegs onand protruding within said recessed portion .of said member, a metal grid mounted on said pegs in said member alongside said filament, an anode plate mounted outside said grid, a glass cap vlaterally on and sealed to said member and mounted outside each said grid, and a glass cap interfitting each side of and sealed to said member.

6. A thermionc valve consisting of astout annular glass member, an incandescible filament mounted across the central aperture of and within the thickness of said member, a metal grid mounted in said member on each side of said lament, an anode plate mounted outside each said grid, a glass cap on each side of and sealed to said member, and a metal liner in each said glass cap in contact with each said anode plate.

7. A thermionic valve consisting of a stout annular glass member recessed on both sides, an incandescible filament mounted across the central aperture of and within the thickness of said member, pegs on and protruding within said recessed sides of said member, a metal grid mounted on said pegs in said .member on each side of said filament, an anode plate mounted outside each said grid against the ends of said pegs, and a glass cap on each side of and sealed to said nember and bearing against each said anode ate.

p 8. A thermionic valve consisting of a stout annular glass member recessed on both sides, an incandescible filament mounted across the central aperture of and within the thickness of said member, pegs on and protruding within said recessed sides of said member, a metal grid mounted on said pegs in said member on each side of said filament, an anode plate mounted outside each said grid. against the ends of said pegs, a glass cap on each side of and sealed to said member and bearing against each said anode plate, and a anged metal liner in each said cap with its flange interposed between e/ach said adjacent cap and each said adjacent anode plate. Y

IIntestimony whereof I have signed my name to this-specification.

ARTHUR ELLIOT BEATTIE.

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